Gardner will officially join Albion on a Bosman transfer on July 1 after passing a medical and putting pen to paper on a three-year deal, plus a further year's option in the club's favour.

Confirming the news in a statement on Tuesday, the Baggies added that they had "beaten off competition from a string of clubs" to secure the services of the 27-year-old.

When he completes his move following the expiry of his Sunderland contract at the end of June, former England Under-21 international Gardner will be with a midlands side for the third time in his career, having previously played for Aston Villa and Birmingham.

West Brom director of football administration Richard Garlick said: "Craig is someone we have followed for a long time and we are delighted to finally get him.

"We tried to bring him here in the January transfer window but it did not work out.

"We have continued to track him and he has expressed a real desire to be at this club following interest from elsewhere.

"He has the flexibility to play in a few positions across the midfield, scores goals, and can slot in at right-back if required.

"I think he will bring a freshness to our midfield area and his character will suit our dressing room.

"We know we have a big summer ahead of us and it is great to get our first signing done so early."

Albion are looking to rebuild after their 2013/14 Barclays Premier League campaign ended with them having slumped to 17th place, just three points clear of the relegation zone.

Change has already been afoot at the club since the conclusion of the campaign, with head coach Pepe Mel leaving by mutual consent.

Terry Burton is to rejoin them as technical director on June 1, one-year options have been exercised on captain Chris Brunt and fellow midfielder Graham Dorrans, while defenders Steven Reid and Liam Ridgewell are among a host of players confirmed as departing.

In Gardner, the Baggies have announced an incoming squad member for the first time this summer and are acquiring someone who has been restricted to just 12 starts in all competitions in 2013/14. He signed for Sunderland from Birmingham in 2011.